ADHD and Dyslexia

ADHD and dyslexia are distinct conditions that frequently overlap, thereby causing some confusion about the nature of these two conditions. AD/HD is one of the most common developmental problems, affecting 3–5% of the school population. It is characterized by inattention, distractibility, hyperactivity and impulsivity. It is estimated that 30% of those with dyslexia have coexisting AD/HD.

Coexisting means the two conditions, AD/HD and dyslexia,can occur together, but they do not cause each other. 

Dyslexia is a language-based learning disability characterized by difficulties with accurate and fluent word recognition, spelling,and reading decoding. People with dyslexia have problems discriminating sounds within a word or phonemes, a key factor in their reading and spelling difficulties. (See IDA fact sheets “Definition of Dyslexia” and “Dyslexia Basics.”)

How are ADHD and Dyslexia diagnosed?

ADHD and dyslexia are diagnosed differently. An evaluation for AD/HD is carried out by a physician or a psychologist. This evaluation should include the following:

1. complete medical and family history
2. physical examination
3. interviews with parents and child
4. behavior rating scales completed by parents and teachers
5. observation of the child
6. psychological tests to measure intellectual potential, social and emotional adjustment, as well as to assess for the presence of learning disabilities, such as dyslexia.

Although AD/HD has been given numerous names since it was first identified in 1902, the Diagnostic and Statistical Manual, 4th Edition.  These subtypes are:

1. ADHD predominantly inattentive type is characterized by distractibility and difficulty sustaining mental effort and attention.
2. ADHD predominantly hyperactive impulsive type is characterized by fidgeting with hands and feet, squirming in one’s chair, acting as if driven by a motor, interrupting and intruding upon others.
3. ADHD combined type meets both sets of inattention and hyperactive/impulsive criteria.
4. Dyslexia is diagnosed through a psychoeducational evaluation. (See IDA fact sheet: “Testing and Evaluation.”) 

Is ADHD over-diagnosed?

The American Medical Association and the Centers for Disease Control and Prevention have concluded that ADHD is not overdiagnosed; however, increased awareness has resulted in an increase in the number of individuals diagnosed with ADHD. Girls and gifted children are actually underdiagnosed or may be diagnosed late. Girls often have ADHD predominantly inattentive type where the essential feature is inattention. This subtype of ADHD can easily be overlooked because the more obvious characteristics of hyperactivity and impulsivity are not present. Gifted children may be identified late because their strong intellectual abilities help them to compensate for these weaknesses in attention.

Can you inherit ADHD and Dyslexia?

Both ADHD and dyslexia run in families. Genetics play a role in about half of the children diagnosed with AD/HD. For the other half, research has yet to identify a cause. Regarding dyslexia, about one third of the children born to a dyslexic parent will also likely be dyslexic.

What do ADHD and Dyslexia have in common?

Dyslexic children and children with ADHD have some similar characteristics. Dyslexic children, like children with ADHD, may have difficulty paying attention because reading is so demanding that it causes them to fatigue easily, limiting the ability to sustain concentration. People with dyslexia and those with ADHD both have difficulty with reading. The dyslexic person’s reading is typically dysfluent, with major problems with accuracy, misreading both large and small words. The person with ADHD may also be a dysfluent reader, but his or her reading is not characterized by misreading words. The AD/HD reader may skip over punctuation, leave off endings, and lose his or her place. The dysfluency of both the ADHD person and the dyslexic reader may negatively impact comprehension. Both may avoid reading and derive little pleasure from it. Both the person with dyslexia and the person with ADHD typically have trouble with writing. The typical dyslexic writer has significant problems with spelling, grammar, proofreading, and organization. The ADHD writer often has difficulty with organization and proofreading. Both the dyslexic writer and the ADHD writer may have handwriting difficulties.

 Individuals with dyslexia and AD/HD may be underachieving in school even though they are often bright and motivated. The goal for them, as it is for all children, is to meet their potential. It is critical that children with these disorders be carefully evaluated because treatment for one disorder is different from the other. Inaccurate diagnosis can lead to inappropriate intervention and a delay in timely, effective intervention.